1. Field of the Invention
The field of the invention relates generally to power regulation, and more particularly relate to reactive power regulation.
2. Description of Related Art
Power sources such as solar panels and wind turbines have received increased attention as environmentally safe and sustainable alternative power sources compared to traditional coal powered power sources. When the power output from the power sources is fed to an electrical grid for transmission and distribution, it is usually necessary to control the reactive power of the output power to fulfill electrical demand while providing stability for the electrical grid.
Conventional reactive power control is based on the assumption that the electrical grid is always symmetrical in three phases. Based on this assumption, the reactive power is regulated by directly adjusting the output power in positive sequence components without considering negative sequence components in the electrical grid. However, in an imbalanced electrical grid, the negative sequence components may lead to second order ripples in the output power. Therefore, the reactive power control is not accurate due to the lack of reactive power regulation with respect to the negative sequence components.
In addition, many countries now require that power sources stay connected with the electrical grid when the electrical grid experiences fault conditions. However, providing accurate reactive power control may be even more challenging during fault conditions.
It is desirable to provide a system and method for regulating reactive power to address the above-mentioned problems.